NEW YORK (Reuters) – Sprint Corp will accelerate investment in its network as it plots a future as a standalone company, its chief executive officer said on Wednesday, days after the No. 4 U.S. wireless carrier and rival T-Mobile US Inc said merger talks had failed.

Sprint CEO Marcelo Claure said at an investor conference the company could spend more than its previous guidance of $5 billion to $6 billion per year on capital expenditures, and that cash on hand could dip next year as it builds out its network.

“We came to the realization that we’re still far away from what the Sprint network can actually deliver,” Claure said on Wednesday. “I don’t think we’ve put all our assets to work.”

Sprint and No. 3 U.S. wireless carrier T-Mobile said on Saturday they have called off merger talks to create a combined U.S. wireless company to rival market leaders ATT Inc and Verizon Communications Inc.

Claure said on Wednesday that the talks fell through because SoftBank Group Corp CEO Masayoshi Son was not prepared to relinquish control of Sprint. SoftBank owns a majority of Sprint shares.

“We’re always going to be open to looking at possible alternatives,” he said, adding that “we believe that eventually there’s going to need to be a tie-up between a telco and a cable company.”

Sprint shares rose 4.2 percent to $5.99 in early afternoon trading on Wednesday.